On Tue, 25 Nov 1997 12:09:47 -0500 k4auw@juno.com writes:
>Hello all,
>
>Wonder if anyone has ever acurately measured a reistor for a parasetic
>supressor before assembly, soldered it to the PS inductor, then
>un-soldered and re-measured the value? I would be interested in the
>value change for various resistor compositions from the heat of the
>solder de-solder process if proper heat sinking was done.
>
>73....Ron
Done it many times while trying new ideas...results...no change.
Of course that is with a 140W gun, not a blowtorch.
73 Carl KM1H
>On Tue, 25 Nov 1997 08:33:28 +0008 "George T. Daughters"
><gdaught6@pobox2.stanford.edu> writes:
>>
>>hi all,
>>
>>rich wrote...
>>
>>> If your amplifier arced mysteriously, it might be interesting to
>>measure
>>> the resistance of the VHF parasitic suppressor resistor.
>>
>>it is perhaps important to note that an increase in the resistance of
>
>>a composition resistor (or a film resistor, too) can increase when
>>the resistor gets too hot. (rich has said this, too.) it doesn't
>>have to be so hot that it bakes the color bands to new colors. the
>>point i want to convey is that it doesn't *have* to be a parasitic
>>oscillation that causes this change. i've seen resistors in dc power
>
>>supplies increase by a factor of 3 or 4 by chronic overheating, but
>no
>>
>>smoke was emitted.
>>
>>73,
>>George T. Daughters, K6GT
>>
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